.github-corner:hover .octo-arm {
 animation:octocat-wave 560ms ease-in-out
}
@keyframes octocat-wave {
 0%,100% { transform:rotate(0) }
 20%,60% { transform:rotate(-25deg) }
 40%,80% { transform:rotate(10deg) }
}
@media (max-width:500px) {
 .github-corner:hover .octo-arm {
   animation:none
 }
 .github-corner .octo-arm {
   animation:octocat-wave 560ms ease-in-out
 }
}
